Review sheet – Marine Biology and Ecology (Chapter 12)
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Understand that marine biology is the study of marine organisms, while marine ecology is the
study of how marine organisms interact with one another and their environment
Know that energy can never be created or destroyed, only transferred or transformed
Understand that primary producers convert light energy into chemical energy via
photosynthesis (or chemosynthesis as seen in hydrothermal vent communities)
Understand that photosynthesis removes carbon dioxide and water and releases oxygen while
forming carbohydrates
Know that primary producers are known as autotrophs
Know that consumers are known as heterotrophs
Understand that marine food webs are very complex and can change with life history (age), food
availability, location and our knowledge (understanding)
Know that levels of the food web are called trophic levels
Understand that primary producers are consumed by primary consumers, and primary
consumers are consumed by secondary consumers, and so on
Know that the arrows in a food web always point to the direction of energy transfer, and so
points to the consumer (and points away from the prey)
Understand that the transfer of energy is never 100% efficient and that only 10% of the energy
stored in “food” is transferred to the next trophic level
Know that the ocean is primarily divided into pelagic (open water) and benthic (bottom) zones
Understand that the pelagic zone is also divided by light (photic, aphotic zone) and depth
Know that the pelagic zone includes the neritic (nearshore) zone and oceanic (deep water) zones
Know that the pelagic community consists of drifting organisms known as plankton, and
swimming organisms known as nekton
Know that the oceanic zone (of the pelagic zone) is subdivided by depth and that these zones
are: epipelagic (upper 200 meters; photic zone), mesopelagic (200-1000 meters; includes photic
zone but has insufficient light for photosynthesis), bathypelagic (1000-4000 meters; cold and
aphotic), and abyssopelagic zone (4000-6000 meters, very deep). Trenches include a fifth zone:
hadopelagic - the deepest of all the zones
Know that 75% of the ocean does not receive sunlight, but life exists here nonetheless
Understand that food is extremely limited in the deep ocean, and that organisms depend on fallout of food from above (carcasses, ‘marine snow’)
Know that adaptations for deep-sea organisms include: small size, slow metabolism, watery
body composition, extendable jaws, hermaphroditism, upward-looking eyes, black or red
coloration, photophores and bioluminescence
Understand that the male anglerfish attaches himself to the female and provides a constant
supply of sperm (adaptive strategy because mates are so sparse)
Understand that the primary producers of hydrothermal vent communities are chemosynthetic
bacteria that use hydrogen sulfide to convert carbon dioxide into organic matter (as plants
would use sunlight)